Base de données de recherche des TNO

Régions: Inuvialuit Settlement Region, Gwich'in Settlement Area, Sahtu Settlement Area, North Slave Region

étiquettes: physical sciences, remote sensing, permafrost mapping, thaw slump, landscape model

Objectif(s): To develop and test new methods of characterizing permafrost and monitoring permafrost landscape change with a focus on the Beaufort Delta, central Mackenzie Valley and North Slave regions.

Description du projet: This licence has been issued for the scientific research application No.5473. The primary objectives of this research are: 1) to develop and test new methods of characterizing permafrost and monitoring permafrost landscape change with a focus on the Beaufort Delta, central Mackenzie Valley and North Slave regions; 2) mapping sensitive permafrost terrain across NWT by integrating expert assessment with remote sensing tools and establish field and aerial inventory methods to validate mapping; 3) to investigate the impacts of natural and human disturbance on permafrost terrain and the ground temperature conditions in natural environments and communities; and, 4) assess the physical and chemical characteristics of permafrost to predict consequences of thaw better. To achieve our objectives, we will implement the following methods: 1. Monitoring permafrost will involve collecting information on the ground ice, ground temperature and terrain conditions at selected sites. Fieldwork will include obtaining permafrost samples from 1-4 m depth using a two-person auger system, installing temperature sensors to maximum depths about 5 m, and conducting surveys to determine the depth to permafrost and vegetation conditions. To monitor change in surface conditions, the team will install heave meters anchored in permafrost and conduct unmanned aerial vehicle (UAV) surveys where appropriate. The UAV is a small fixed-wing device with an optical and thermal camera, and the surveys are typically 20-40 minutes in duration. All activities will be compliant with Transport Canada regulations. Ecologically or culturally sensitive areas will be avoided unless surveys are requested by local communities or assist a regulatory organization. Repeat surveys enable the team to visualize landforms and monitor change in disturbances impacting the landscape. These field sites will typically be close to communities or in areas deemed important for monitoring. As such, they provide opportunities for community engagement and training, as has been the case with Inuvialuit Environmental Monitors and their involvement with monitoring ground temperatures along the Inuvik to Tuktoyaktuk Highway. The monitoring sites also allow the team to determine if high-resolution satellite imagery can be used to track landscape changes affecting remote regions or critical infrastructure corridors. The team will also utilize remote cameras to visualize, and model the development of unstable slopes, thaw slumps and icing development. 2. Mapping of sensitive permafrost terrain has involved developing a rubric with input from experts across Canada. Trained mappers have started to map sensitive terrain around NWT communities and key infrastructure corridors. Mappers are situated at several Academic institutions, in Yellowknife at NWT Geological Survey and the Aurora Research Institute in Inuvik. A workshop in Fort Simpson was conducted to introduce community members to mapping methods, and the team has worked with Inuvaluit Land Administration (ILA) and Inuvaluit Jiont Secretariat (IJS) to plan a tentative mapping workshop in 2021, which could take a virtual format if necessary. Mapping is a desktop activity we can proceed with under COVID restrictions. The team has also developed a method for inventorying permafrost features and thermokarst landforms which will be implemented by conducting aerial surveys from a helicopter. The landscape assessments involve flying transects at an altitude of about 300 to 500 m that extend from Inuvik, Norman Wells and Yellowknife. Aerial assessments of permafrost terrain include a landscape interpreter, a photographer and a data recorder who enters information using the Survey 123 © App. The surveys facilitate opportunities for training community monitors and students in landform identification. This activity will be pursued as NWT COVID regulations, and partner policies will permit. The inventories of georeferenced features and photographs will validate broad-scale map products and inform the design of the NWT Permafrost Monitoring Network. 3. To monitor changes in areas affected by permafrost disturbances, the team will conduct field and UAV surveys to build three-dimensional landscape models. These surveys will be complemented at some locations by shallow and deep ground temperature cables and instruments that will measure surface displacement. At several sites in the Yellowknife and Beaufort Delta region, this instrumentation is in place from past projects, but as community, scientific and regulatory concerns emerge the team may instrument additional locations. As indicated above, the installation would involve a portable drill operated by a two-person crew and drilling depths would not exceed 10 m. The research team will maintain sites and continue ground temperature data collection at all existing locations and any sites newly installed. 4. The physical and chemical characteristics of permafrost will be evaluated by obtaining samples from permafrost. These can be collected by a small two-person portable drill (CRELL drill), or by carefully sampling the permafrost exposed by the headwalls of thaw slumps. Larger thaw slumps can only be safely accessed in winter. The samples will be analyzed for ice content and geochemistry to help determine the environmental consequences of thawing. The research team has a long history of working closely with communities in the Gwich’in and Inuvialuit Settlement Regions. This project is part of the continuation of a multi-year project conducted in close collaboration with the Tetlit and Ehdiitat Renewable Resource Councils and the Inuvialuit Land Administration that has studied permafrost conditions along infrastructure corridors and the impacts of permafrost thaw on streams and rivers. The research team are in the process of discussions with Norman Wells and Yellowknife, and will be meeting with land managers in the Tlicho government. Team members have increasingly interacted with Northern Regulators, Indigenous monitoring programs and Department of Infrastructure in an advisory role. They will continue to do so as permafrost issues become increasingly recognized as priority issues in development planning and climate change adaptation. In the past, the team have communicated our research in the following ways, and will continue using these methods in the future: 1) Yearly plain language presentations (ie: Inuvialuit Game Council meetings; Regional RRC meeting; Local RRC and Hunters and Trappers Committee meetings); 2) Plain language summaries; 3) Presentations to students in local schools (Yellowknife and Inuvik) and the Environment and Natural Resource and Technology Program; 4) Northern conferences, including NWT Cumulative Impact Monitoring Program results workshops, NWT Geoscience Forum, NWT Project Management Conference; 5) Local media; 6) Public Lectures. The fieldwork for this study will be conducted from April 1, 2023 to October 15, 2023.